Chronic Recurrent Multifocal Osteomyelitis

Chronic recurrent multifocal osteomyelitis (CRMO) is a bone disorder of children and young adults that is characterized by chronic, multifocal, aseptic inflammation with relapses and exacerbations. While typically self-limited, if untreated, CRMO can cause growth disturbance, early physeal fusion, and pathologic fractures.

The typical imaging findings of CRMO include lytic and sclerotic lesions in the metaphyses of long bones and the medial clavicles, vertebral bodies, pelvis, ribs, and mandible. Hematogenous osteomyelitis also tends to involve the metaphyses and metaphyseal equivalents; however, involvement of the medial clavicles is rare in hematogenous osteomyelitis.

Radiographs initially show osteolytic lesions adjacent to the physis in the metaphysis. Sclerosis then develops around the lytic lesions. Chronic lesions may be predominantly sclerotic and demonstrate hyperostosis. During exacerbations, radiographs may show new lytic lesions with periosteal reaction.

Differential diagnosis:

• subacute and chronic infectious osteomyelitis
• histiocytosis
• hypophosphatasia
• leukemia, lymphoma, and Ewing sarcoma

References

Khanna G, et al. Imaging of Chronic Recurrent Multifocal Osteomyelitis. Radiographics. 2009;29(4):1159-77.